This invention relates to a mineral winning plough having a multi-part sword plate.
Mineral winning ploughs having multi-part sword plates are well known (see, for example, DE-PS No. 1,208,270, DE-OS No. 1,300,889 and DE-PS No. 2,111,224). The sword plate of this known type of plough is usually of three-part construction, having two outer sword plate parts pivotally attached to a middle sword plate part. The pivotal connections between the sword plate parts permit relative pivoting therebetween in the plane perpendicular to both the seam and the floor of a longwall working along which the plough is reciprocably driven. The outer sword plate parts are provided with guide blocks which are guided within a chain guide provided at the goaf side of a conveyor which extends along the working, the plough being reciprocably driven along the face side of the conveyor. The guide blocks are attached to a plough drive chain housed within the chain guide, the sword plate passing underneath the conveyor.
The disadvantage of this known type of plough is that its sword plate, which is loaded by the weight of the conveyor, is subjected to considerable wear. The wear of the sword plate is concentrated in those regions which lie underneath the side walls of the conveyor. Unfortunately, the pivotal connections between the sword plate parts are located in these regions. Consequently, the pivotal connections are subjected to excessive wear, and this can lead to the complete destruction of the pivotal connections.
An object of the invention is to provide a plough having a multi-part sword plate having a strong and simple configuration at its pivotal connections.
Another object of the invention is to provide a plough having a multi-part sword plate whose pivotal connections are not subject to the excessive wear of the pivotal connections of known ploughs.
Yet another object of the present invention is to provide a plough having a multi-part sword plate, the parts of which are easy to assemble and dismantle.